Electronic messages come in many forms, including the rudimentary electrical telegraph to the modern instant messaging systems. Electronic mail (email), a common form of digital messaging, is largely a store-and-forward model, where emails to a recipient were stored for the recipient until the recipient connected to the mail server and retrieved the email. Various forms of text messaging have been available ranging from internet relay chat (IRC), short message service (SMS), and proprietary systems (e.g., AOL Instant Messenger).